On the concept of activity in the last papers of Nikolai Bernstein.

In this paper, we analyze Nikolai Bernstein's notion of the activity of living organisms, which he introduced at the end of his career. Bernstein did not leave a systematic description of his last thoughts, but many remarks in his writing, especially in his last book [Bernstein, 1966], show that he thought deeply about the biological significance of the ideas that he developed while studying motor control. He accepted that negentropy (the tendency towards probabilistic determinacy, orderliness, free energy expenditure) is a hallmark of all life processes but wrote extensively about the insufficiency of this property and searched for a more complete definition of living organisms. This definition would include the goal-directedness of development, anticipation, persistence, tendency toward autonomy, initiative, and more. Thus, this paper is an attempt to present the definition of the activity of living organisms from Bernstein's later work to English-speaking readers.

IL-15 controls T cell functions through its influence on CD30 and OX40 antigens in Celiac Disease.

AIM: To evaluate the ability of interleukin (IL)-15 to control T cell functions through its influence on CD30 and OX40 expressing cells in Celiac Disease (CD). In peripheral blood (PB), by examining the expression of OX40 in conventional effectors cells and T cells with a phenotypic specialization of regulatory cells [CD4+CD25high forkhead box protein 3 (Foxp3)+], and the co stimulation of IFN-γ and IL-4 production within CD30 and OX40 positive subsets of T cells. At the duodenal mucosa, by assessing the expression of CD30 and OX40 in intraepithelial (IE) and lamina propria (LP) lymphocytes (IEL, LPL). PATIENTS AND METHODS: PB and duodenal mucosal biopsies were obtained from 38 patients with classic CD (Cel) and 38 healthy controls (HC). Analysis of cell surface and/or intracellular antigens was performed in anti-CD3-treated PB mononuclear cells (PBMC) before and after treatment with recombinant IL-15 (rIL-15), and in IE and LP cellular suspensions prepared from duodenal biopsies pre-treated with/without rIL-15. RESULTS: A subpopulation of CD3+OX40+ T blasts was induced in Cel and HC by a 3days treatment of PBMC with anti-CD3 and decreased its size thereafter, regardless of the presence of rIL-15. However, the addition of rIL-15 to T blasts distinctively induced the survival of T cells with a regulatory phenotype that expresses OX40 antigen in Cel (p<0.05). Celiac patients showed higher frequencies of IFN-γ-producing CD3+CD30+ blasts before and after treatment with rIL-15 (p<0.05, vs. HC). IL-15 increased the frequencies of CD3+CD30+ LPL (HC: p<0.05, Cel: p<0.05) but not of CD3+OX40+ LPL, and CD30 or OX40 positive IEL. CONCLUSIONS: The distinctive control of OX40+ cells with a T regulatory phenotype mediated by the influence of IL-15 comes out as new function of this cytokine in the context of CD. The higher production of IFN-γ by a subpopulation of peripheral CD3+CD30+ cells contributes to the type I biased immune response.

Alterations in innate and adaptive immune leukocytes are involved in paediatric obesity.

BACKGROUND: Adipose tissue is the main source of the cytokines and adipokines that are increased in the context of obesity. The production of reactive oxygen species (ROS) and cytokines by circulating immune cells can be regulated by these pro-inflammatory factors even before infiltration into adipose tissue. OBJECTIVE: To investigate the alterations that can occur in circulating monocytes and lymphocytes in paediatric obesity. METHODS: In this study, 54 paediatric obese patients and 30 age-matched metabolically healthy individuals were enrolled. Intracellular cytokines were analyzed after phorbol myristate acetate (PMA) or leptin plus PMA stimulation of lymphocytes and monocytes by flow cytometry. ROS generation was measured using dichlorofluorescein-diacetate. Both a 'stimulation index' and a 'fold of increase' were calculated for statistical purposes. RESULTS: Both interferon gamma (IFN-γ) production by circulating CD4+ and CD8+ lymphocytes and ROS production by monocytes following PMA stimulation were increased in obese patients. Leptin induced an increased production of IFN-γ in both subsets of T cells and tumour necrosis factor alpha in monocytes, and linoleic acid induced a higher ROS production in monocytes. CONCLUSIONS: The distinct functional responses of circulating cells suggest that alterations in both innate and adaptive immune cells are involved in the maintenance of low-grade inflammation in paediatric obesity.

Altered expression of the lymphocyte activation antigen CD30 in active celiac disease.

Interleukin (IL)-15 and CD30 may be associated with the ongoing intestinal immunologic activation in celiac disease (CD). We studied duodenal biopsies and blood samples of patients with active CD (Cel) and controls in order to determine the regulatory role proposed for CD30(+) T cells in this Th1-driven disease and the potential influences of IL-15 on CD30 expression. We detected that a CD30(+) T-cell subpopulation persists longer in Cel after a 5 day incubation with anti-CD3 antibody than in controls (p = 0.0063). CD30 upregulation by IL-15 in T blasts was greater in Cel than in controls (p = 0.0062). At the mucosal compartment, the CD30 antigen was examined by immunohistochemistry and quantified on isolated lamina propria (LP) and epithelial T cells by flow cytometry. For Cel and controls, similar mean percentages of CD3(+)CD30(+) intraepithelial T cells (5.88 vs. 5.51, p = ns) and LP T cells (7.38 vs. 7.49, p = ns) were observed at baseline and after in vitro gliadin challenge of duodenal biopsy samples. Our study demonstrates the occurrence of potentially important alterations of the immune response at the peripheral compartment. Our findings also allow us to speculate that a negative effect of soluble mediators at the mucosal compartment might counteract the latent influence of IL-15 on CD30 expression precluding a more severe course of active CD.

Liver infiltrating mononuclear cells in children with type 1 autoimmune hepatitis.

OBJECTIVE: To investigate infiltrating cells in the liver of children with type 1 autoimmune hepatitis (AH-1). METHODS: liver biopsies from 24 untreated AH-1 patients (14 children, 10 adults), five patients with hepatitis C virus related chronic hepatitis (HCV), and 10 control liver specimens (CL) were processed for immunohistochemical cell characterisation. RESULTS: Two different cell distribution patterns were detected in the liver of patients with AH-1: (1) CD4(+) and CD20(+) cells were found in the central areas of the portal tracts (portal distribution); (2) CD8(+) cells were observed at the periphery of the portal space (periportal distribution). Some cell subsets, like CD56, CD57, Fas-L, and Bak, showed a non-defined distribution pattern. The presence of two well defined patterns of cell distribution was not observed in HCV and CL (CD4(+), CD20(+), and CD8(+) cells were uniformly distributed in the portal space). In AH-1 and CL, the NK markers CD56 and CD57 were found scattered throughout the liver parenchyma. However, in HCV biopsies, CD56(+) cells were also clearly increased in both the portal and the periportal areas. Biopsies of AH-1 and HCV patients showed a uniform distribution of Fas-L and Bak in the portal and periportal areas, with Bak staining also detected in the hepatic parenchyma. CONCLUSIONS: Despite clinical and genetic differences, there was a similar distribution of liver infiltrating mononuclear cells in children and adults with AH-1. These results raise the possibility of reclassifying cryptogenic chronic hepatitis by immunohistochemical analysis of infiltrating liver cells.

The IL-1 gene family and bone involvement in celiac disease.

Celiac disease (CD) is associated with decreased bone mineral mass. Its pathogenesis is multifactorial since both systemic and local mechanisms may play a role. Our objective was to determine whether single-nucleotide polymorphisms in genes encoding members of the interleukin-1 family are associated with bone damage measured by densitometry in a series of 71 adult CD patients assessed at diagnosis. When compared with non-carrier CD patients, carriers of allele T of the interleukin-1beta gene (IL1B-511T) had a significantly lower bone mass at the total skeleton level (p = 0.0484) and a greater prevalence of osteopenia/osteoporosis (p = 0.0102). To our knowledge, this is the first evidence on the association between a genetic predisposition and low bone mass in CD patients. This finding supports the postulated inflammation-associated bone loss pathogenesis as one of the causes of bone weakness in CD.

Overexpression of neutrophil neuronal nitric oxide synthase in Parkinson's disease.

Much evidence supports a role of nitric oxide (.NO) and peroxynitrite (ONOO(-)) in experimental and idiopathic Parkinson's disease (PD); moreover, an overexpression of neuronal nitric oxide synthase (nNOS) was recently reported in the basal ganglia of PD patients. In accord, we previously found a 50% increased.NO production rate during the respiratory burst of circulating neutrophils (PMN) from PD patients. As PMN express the nNOS isoform, the objective of the present study was to ascertain whether this increased.NO production is representative of nNOS gene upregulation. PMN were isolated from blood samples obtained from seven PD patients and seven age- and sex-matched healthy donors; nNOS mRNA was amplified by reverse transcriptase-polymerase chain reaction and the products were hybridized with a probe for nNOS. Nitrotyrosine-containing proteins and nNOS were detected by Western blot and NO production rate was measured spectrophotometrically by the conversion of oxymyoglobin to metmyoglobin. The results showed that both.NO production and protein tyrosine nitration were significantly increased in PMN isolated from PD patients (PD 0.09 +/- 0.01 vs 0.06 +/- 0.008 nmol min(-1) 10(6) cells(-1); P < 0.05). In addition, five of the seven PD patients showed about 10-fold nNOS mRNA overexpression; while two of the seven PD patients showed an expression level similar to that of the controls; detection of nNOS protein was more evident in the former group. In summary, it is likely that overexpression of nNOS and formation of ONOO(-) in PMN cells from PD patients emphasizes a potential causal role of.NO in the physiopathology of the illness.

Immune complexes inhibit apoptosis of chronic lymphocytic leukaemia B cells.

In the present study we examined the effect of immune complexes (IC) on the survival of chronic lymphocytic leukaemia (B-CLL) B cells. Our results showed that either precipitating IC (pIC), Ab-coated erythrocytes (E-IgG) or heat-aggregated IgG (aIgG) significantly inhibited spontaneous apoptosis of B-CLL cells, as well as that induced by fludarabine, chlorambucil or dexamethasone. After depletion of T lymphocytes, monocytes and NK cells, incubation with IC was no longer able to delay B-CLL cells apoptosis, suggesting that prevention of apoptosis depends on IC interaction with accessory leucocytes. The release of IFNgamma by non-malignant cells upon activation with IC was responsible, to some extent, for IC effects as shown by the fact that neutralizing anti-IFNgamma MoAb partially prevented their ability to inhibit B-CLL cells apoptosis. The observation that treatment with IC resulted in increased expression of HLA-DR on B-CLL cells suggests that inhibition of apoptosis is associated with cellular activation.

N-formyl-methionyl-leucyl-phenylalanine (fMLP) inhibits tumour necrosis factor-alpha (TNF-alpha) production on lipopolysaccharide (LPS)-stimulated human neutrophils.

During gram-negative infections bacterial components, such as LPS and formylated peptides, exert profound physiological effects on polymorphonuclear neutrophils (PMN) resulting in increased neutrophil effector activities, including the generation of oxidative metabolites, degranulation, phagocytosis and cytokine release. There is not enough evidence about the relationships between LPS and formylated bacterial peptides in the triggering and regulation of the immune inflammatory response. In this study, we present evidence indicating that pretreatment of human PMN with a prototype formylated peptide such as fMLP results in the inhibition of TNF-alpha secretion, a key molecule that plays a central role in the pathogenesis of septic shock. This inhibitory effect of fMLP does not appear to alter the expression of LPS receptors or the transcriptional pathway of the TNF-alpha mRNA, but instead, fMLP reduces the expression of the membrane form of TNF-alpha on the PMN surface. These findings indicate that fMLP, a typical proinflammatory agent, could play, at least in determined conditions, an anti-inflammatory role.

Tacaribe virus gene expression in cytopathic and non-cytopathic infections.

Tacaribe virus (TV) replication was compared in Vero cells infected under conditions leading either to cell death (c.p.e.(+) infection) or to the establishment of persistence (c.p.e.(-) infection). To this end, two virus preparations were employed: one containing a ratio of standard (plaque-forming) viruses to interfering particles (IP) that would induce a distinct lytic response in Vero cells infected at multiplicities giving synchronous infection and another virus stock enriched in IP that would block the cell-killing potential of the cytolytic virus stock. The following results were obtained: (1) No qualitative differences were observed in the species of intracellular viral RNAs in the lytic infection in comparison with infections leading to persistence or during the early stages of persistence. (2) Levels of viral RNAs were severely reduced when the cells were infected with IP in addition to standard viruses, the RNA accumulation being inversely proportional to the ratio of IP to standard viruses used in the infections. (3) Accumulation of the three measurable mRNAs (those corresponding to the glycoprotein precursor [GPC], to the nucleoprotein [N], and to the p11Z protein) ended earlier in the c.p.e.(-) infections (around 18 hr p.i.) than in the c.p.e.(+) infection (45-68 hr p.i.). (4) The rates of synthesis of the GPC, N, and p11Z proteins were largely determined in both the c.p.e.(+) and c.p.e.(-) infections by the amounts of their corresponding mRNAs. (5) The kinetics of accumulation of the S genomes and also the ratios of the S genome to S antigenome were similar in the different infections (accumulation ending at 45-68 hr p.i.). (6) L genome accumulation proceeded for longer time (until 92 hr p.i.) in the c.p.e.(+) infection than in the c.p.e.(-) infections. In the latter accumulation ended at around 45 hr p.i. Until this time ratios of L genome to L antigenome were similar in the different infections. It is concluded that IP affect virus mRNA synthesis early after infection reducing in this way the rate of viral protein synthesis. Low levels of viral proteins might then limit virus replication. In addition, the results support the idea that in TV infections transcription and replication are independently regulated. The implications of these results with regards to the nature and mode of action of TV IP are discussed.

Haloperidol and oestrogens induce c-myc and c-fos expression in the anterior pituitary gland of the rat.

Decreased dopaminergic and increased oestrogenic effects induce prolactin release and DNA synthesis in prolactin secreting cells of the adult male rats. Oestrogen treatment for 7 days significantly increased the levels of prolactin, c-myc and c-fos mRNAs. The effect of oestrogens was reversed by the administration of the dopaminergic agonist bromocriptine. There was an early gradual increase of c-myc mRNA levels beginning 30 min after the injection of the steroid. c-fos mRNA levels increased sharply 15 min after oestrogen administration and decreased to basal values 15 min later to remain at this level over the period of time evaluated. Administration of the dopaminergic antagonist haloperidol did not change the levels of protooncogenes mRNA. However, in rats previously treated with oestrogens for 7 days c-myc mRNA levels increased 90 min after the injection of haloperidol and decreased to basal values after 2.5 h. c-fos mRNA levels increased sharply 30 min after haloperidol administration and also decreased to basal values 1 h later. We propose that changes in protooncogenes expression may be involved in the stimulation of cell proliferation induced by prolactin secretion.

Human pituitary tumours: studies on genes expression.

Searching for differences in gene expression between different types of human pituitary adenomas, we evaluated the concentration of mRNA from hormonal genes (prolactin and growth hormone) and oncogenes (c-myc and c-fos) in 12 growth hormone-secreting 7 prolactin-secreting and 11 nonsecreting adenomas. We found a positive correlation between clinical diagnoses and hormonal gene expression in all the cases. Our reports indicate the presence of c-myc and c-fos mRNA in all the adenomas evaluated. The concentration of c-myc mRNA was higher in somatotrophic adenomas than in prolactinomas and nonsecreting adenomas whereas c-fos mRNA concentration was similar in the different types of tumours analysed. Oncogenes products, in turn, might stimulate DNA synthesis and cell proliferation and eventually lead to the formation of pituitary adenomas. This is a working hypothesis.

Indomethacin inhibits the effects of oestrogen in the anterior pituitary gland of the rat.

Two inhibitors of prostaglandin synthesis, indomethacin and aspirin, blocked the increase of oestrogen-binding sites in the nuclear subcellular fraction, an increase which occurs after the administration of oestradiol. Consequently the biological effects of oestrogens in the anterior pituitary gland of the rat (prolactin synthesis, concentration of progesterone-binding sites and cell proliferation) are diminished. The anterior pituitary gland synthesized prostaglandin F2 alpha (PGF2 alpha), PGE2 and PGD2 from arachidonic acid. This synthesis was blocked when indomethacin was added to the culture media. Oestrogen increased the concentration of PGE2: an increase that was partially prevented by indomethacin. Prostaglandins may have an important role on the effects of oestrogen in the anterior pituitary gland of the rat.

Effect of antineoplastic drugs and estradiol on leucine uptake and proliferation of Ehrlich tumor cells.

Antineoplastic drugs (methotrexate, 5-fluorouracil, adriamycin) arrest the proliferation of Ehrlich ascites tumor cells in mice but have no influence on L-leucine uptake in vitro. Tamoxifen does not influence either process. Estradiol increases both the cellular proliferation and the amino acid uptake. The absence of estrogen receptors in the cells indicates that the hormone acts on cellular proliferation through mechanisms other than activation of DNA replication, such as stimulation of amino acid transport.